Mobile devices are self-contained, such as for example cordless screwdrivers, which are equipped with an internal voltage source, especially an accumulator. With stationary devices, the voltage supply generally is provided from the outside, e.g. via the regular power grid.
The liquid cartridge is also referred to as a storage container. It usually contains ink or a solvent. In general, it contains a liquid required for the printing process. Regarding ink cartridges, reference is made to WO 2013/120702 A1, the disclosure of which is fully incorporated by reference as part of the present disclosure. In practical operation, the reservoir is required to be replaced quite often, as the liquid is constantly used up during printing and the reservoir is depleted after a certain number of printing operations.
According to prior art, the liquid cartridge has a cap comprising a rubber layer, a plastic layer and a holder. The holder overlaps the opening of the cartridge, which is usually formed by a connector stub. The holder is fastened to the connector stub and has a window. The rubber layer and the plastic layer are situated underneath the window, each one overlapping and closing the opening. Such a storage container is filled by first puncturing the layer assembly of the rubber and plastic layers with a hollow needle. The liquid, for example solvent or ink, is then filled into the liquid cartridge, specifically into its film bag, via the hollow needle.
In prior art, it is assumed for the sheet assembly of the rubber layer and plastic layer to automatically re-close the opening or the hole as soon as the hollow needle is withdrawn. However, this does not always apply. The rubber layer material can be used for sealing. The plastic layer supports the rubber layer. The rubber layer has a certain stiffness. The hollow needle tears a hole that does not always completely close when retracting the hollow needle, instead, bending open and mutual overlapping of the hole occasionally occurs, thus preventing sufficiently tight closure. Even if a closure is achieved, it is not permanent. With environmental conditions changing, for example changes in temperature or air pressure, conditions are changing too, which also applies to gassing of the solvents. The pressure within the reservoir can be lower and/or higher than ambient pressure. If it is larger, the punctured area may be pressed open. Droplet discharge or even discharge of a fine stream may then be observed. This becomes of particular importance, if the ink is to be filled in under pressure. It should be possible for overpressurized ink or solvents not to be discharged from the opening site of the layer assembly.